[lucasborka]

Hi guys!

I would like to have some feedback about my boost spike problem. Stage 2 91 octane

Car spec:
BMW 435i 2015 48k miles
Vrsf IC
Vrsf catless Dp
Fresh oem bosch plugs
And aluminium chargepipe

I'll post 3 logs but they are all the same, the boost spikes at low rpm and then it cannot hold boost targets and the wastegate is working very hard at high rpms.

Recently changed o-rings on IC and chargepipe but it doesn't helped. I'm going to pressure test also next week

Log 1: https://www.bootmod3.net/log?id=6079...729b05a6a061b2

Log 2: https://www.bootmod3.net/log?id=6079...0b43443dbc9256

Log 3: https://www.bootmod3.net/log?id=6079...90c62c0ecf046d

All Done in 4th gear dsc off, no throttle clusures

[n55david]

havw you checked your diverter valve?

[lucasborka]

Originally Posted by Phantom10R

havw you checked your diverter valve?

No.. I have ordered a pressure tester. Can I test it without a pressure tester?

[thejeremyman9]

I am really not sure what your concern is? This looks like every other BM3 stage 2 OTS map log - overboost at low RPM then slightly under target at higher RPM. That's basically the way the BM3 maps are designed, they allow boost to exceed target (in most cases, especially right at tip in) without throttle closure. WGDC in the upper 80s/low 90s at high RPM, especially over 6k, seems on par with other logs. So i just don't see a "boost spike problem" unless im missing something.

https://f30.bimmerpost.com/forums/sh....php?t=1732327

[lucasborka]

Originally Posted by thejeremyman9

I am really not sure what your concern is? This looks like every other BM3 stage 2 OTS map log - overboost at low RPM then slightly under target at higher RPM. That's basically the way the BM3 maps are designed, they allow boost to exceed target (in most cases, especially right at tip in) without throttle closure. WGDC in the upper 80s/low 90s at high RPM, especially over 6k, seems on par with other logs. So i just don't see a "boost spike problem" unless im missing something.

https://f30.bimmerpost.com/forums/sh....php?t=1732327

Okay, Thank you for the feedback. Maybe wrong title on the post 😅 I just thought that it was overboosting at the beginning and then running out of steam.

If you look at the wgdc almost att revline it bounces alot and I could really feel it in the car. It kinda jerks a little bit after 6k rpm